Johnson 100hp v4 weird cooling issue

[homelessduck]

I'm back at work on the boat I bought last year and never got fixed. It's a 1968 Johnson v4 Golden Meteor, electramatic , and has the belt driven distributor. I don't get water passed the thermostat housing. When looking at the rear of the engine, the hole on the far right of the block/thermostat housing mating surface shoots water out with the thermostat housing removed. . The problem is the thermostat housing side has no port for it, it is blocked. Were there multiple thermostat housing's produced for these engines ? I'm wondering if I have the wrong one. Mine looks the same as what I've seen on Google, and I haven't seen any other style .. The block has 3 cooling passages, and the thermostat housing has 2 ..

Any help is greatly appreciated.

-Dallas

 

[homelessduck]

Re: Johnson 100hp v4 weird cooling issue

Bump. I would really love to fix this before the 4th.

 

[homelessduck]

Re: Johnson 100hp v4 weird cooling issue

I took a few pictures to better help show what I'm talking about. In this picture : http://i43.tinypic.com/se86iq.jpg the water was only flowing out of the water jacket on the far right, which is blocked off by the thermostat housing.

Here is a picture of the housing.
http://i39.tinypic.com/idg003.jpg
In this picture, the hole on the far left, which doesn't go anywhere, is where the water is flowing to.

 

[F_R]

Re: Johnson 100hp v4 weird cooling issue

I think you are barking up the wrong tree. But to answer your first question, there is only one thermostat housing to fit that motor, and it is the one you show in your picture.

I seem to have a very hazy recollection of discovering the same thing 50 years ago that you are now experiencing. But sorry, can't remember everything about it. HOWEVER, I do believe the water flows from the heads to the thermostat housing through the two molded hoses. Not from the thermostat housing to the heads, which you seem to be thinking. So don't be wasting your time trying to figure out why that isn't happening or what that hole is for. I've already been there.

 

[homelessduck]

Re: Johnson 100hp v4 weird cooling issue

Assuming that hole does nothing , that leaves me with the two other holes. The one on the far left bubbles in the water when I blow compressed air through it. The other one I can't tell where it's going. When I blow through the heads the air comes out of the other head.

Does that tell me anything?

Thanks for the help!

-Dallas

 

[boobie]

Re: Johnson 100hp v4 weird cooling issue

As F_R said, the water flows FROM the heads to the thermo hsg and then out the exhaust hsg. Post a model # as the '68 ignition was not belt driven.

 

[homelessduck]

Re: Johnson 100hp v4 weird cooling issue

Model # V4TL-13A
Serial # J2718137

I hooked everything back up today, with the thermostat and valves in the thermostat housing, which .. due to bad timing and luck I apparently haven't tried. I ran it for about 7 minutes and it seems to be working great. The heat exchanger plate now stays around 90* , and the heads are about 120* . This is with an infared temp gun.

Apparently everything has to be in place so it can build pressure and flow where it's suppose to. When I got the boat I got it running, saw water coming from the exhaust and thought the engine was toast. Then I learned that it's suppose to on this engine. I then thought since it was barely coming out I must have bad water flow so I took the thermostat housing off to inspect. From then on I have tried everything BUT running it with the thermostat and valves in place. I feel stupid, but I'll give myself some leniency since it's my first boat .

Now .. It smokes a lot of blue smoke. It hasn't been ran since '06 so I'm hoping it just needs to be.cleaned / cleared out (?) . I'm going to toss some seafoam in the gas and take it out to the lake for some wot runs and see if it clears up.

Thanks guys!

 

[boobie]

Re: Johnson 100hp v4 weird cooling issue

Do a good decarb on it and see what happens.